1. Field of the Invention
The present invention generally relates to liquid containing bags, liquid cartridges, image forming devices, and sealing methods and sealing apparatuses for the liquid containing bags.
2. Description of the Related Art
An ink jet recording device is known as an image forming device or an image recording device such as a printer, facsimile, or copier. In the ink jet recording device, ink is jetted from a recording head to a form so that recording can be performed. Here, the form includes not only paper but also OHP (Overhead Projector) film and means a material where an image is formed. The form is also called a recorded medium, a recording medium, a recording paper, or the like. It is possible to record a high precision image at a high speed by an ink jet recording device on a recording medium. In addition, running cost is cheap and noise is small in the ink jet recording device. Furthermore, it is easy to record a color image by using a lot of kinds of colors, in the ink jet recording device.
As the above mentioned ink jet recording device, a shuttle type ink jet recording device is generally used. In the shuttle type ink jet recording device, an ink tank (ink cartridge) is installed in a carriage which performs a reciprocating motion along a recording medium with a recording head in a body. There is a limitation to the amount of ink to be installed in such a carriage installed type ink cartridge. Because of this, an ink cartridge main body installed type ink jet recording device, wherein the ink cartridge is provided at a fixed part of a main body of the device and the ink is supplied to the carriage through a flexible pipe, is used so that a large amount of forms can be printed.
Meanwhile, as for a structure of the ink cartridge, in a case of the carriage installed type, ink is absorbed by a capillary force of a porous body installed in the cartridge, and hole diameters of the porous bodies and an ink filling amount are controlled, so that pressure of ink supplied to a recording head is controlled to be a negative pressure. Such an ink cartridge type has been widely used.
On the other hand, in the case of the ink cartridge main body installed type, a function to control the pressure of the ink supplied to the recording head is provided to the carriage of the main body of the device. Hence, in the ink cartridge, an ink bag which contains a large ink amount wherein the ink can be supplied in a sealed state, is advantageous and utilized.
A cartridge wherein a housing which is formed by a solid rectangular shell is filled with ink as discussed in Japanese Laid-Open Patent Application No. 10-202901, and a cartridge which has a flexible ink bath which has a bag configuration, an ink outlet, and a chassis part (housing) having an opening part through which the ink bath can be taken into and out from the chassis part as discussed in Japanese Laid-Open Patent Application No. 10-202900, are also known.
Furthermore, an ink cartridge shown in FIG. 1 is also known. This cartridge includes an ink containing part 501 for containing ink, a case 502 having a tube configuration for containing the ink containing part, and a cover member 503 for covering a front surface of the case 502 having the tube configuration. A holding member 504 is provided to the ink containing part 501 in a body. The holding member 504 has an ink filling opening part 505 for filling the ink containing part 501 with ink, which is sealed and has a pipe configuration, and an ink supply opening part 506 for supplying the ink, which also has a pipe configuration. The holding member 504 is pushed into the case 502 so that a projection part 504a of the holding member 504 is engaged with a receiving hole forming part 502a provided on a wall surface of the case 502 and the holding member 504 is fixed and held to the case 502. Furthermore, the cover member 503 is fit into an opening part of the case 502.
The ink containing part 501 is formed by making the holding member 504 and a frame body 511 in a body and melt-fusing a film-shaped member 512 to the outside of the frame body 511. The inside of the film-shaped member 512 is formed by a resin film and the outside of the film-shaped member 512 is formed by an aluminum film.
Meanwhile, aqueous ink is mainly used for an ink jet recording device. The aqueous ink is manufactured by a process for mixing and scattering raw materials and by a process for filtering the raw materials. If the ink tank is filled with the ink manufactured by the above mentioned processes without any change so that recording is performed, various gases dissolved in the ink such as nitrogen, oxygen, and carbonic acid gas are changed to bubbles in an ink flow path before/in the recording head. This causes bad recording such as dot-off.
In order to solve the above mentioned problem, a deaeration process for reducing dissolved gas in the ink is performed before the ink tank is filled with the ink. A method for decompressing and stirring the ink in a pressure container or a method for deaerating by a deaeration device using a gas separation film is used as a method for the deaeration process.
It is required to fill and seal the ink bag containing the ink deaerated by the above mentioned method without allowing air into the bag. Hence, as discussed in Japanese Laid-Open Patent Application No. 10-193635, a method by which the ink is poured into an ink bag provided at a decompression room in a state where the exterior of the ink bag is compressed, and the ink is sealed in the ink bag without allowing air into the ink bag by heating, melting, and sealing (melt-sealing) the bag without any change, has been known.
However, according to the above mentioned method, it is necessary to provide a decompression room and a mechanism for melt-fusing (melt-sealing) the ink bag in the decompression room. As a result of this, the entire device for filling and sealing the ink bag is complex and expensive. Furthermore, since the volume to be decompressed becomes large and therefore time for decompressing becomes long, so that a productivity is reduced.
Because of this, as discussed above with reference to FIG. 1, it is possible to improve reliability and secure productivity by providing ink opening parts, namely an ink supply opening part for supplying the ink into the outside, and an ink filling opening part for filling the inside of the ink bag with ink, discharging gas existing on the inside from the ink filling opening part, filling the ink bag with the ink via the ink filling opening part, and sealing the ink filling opening part. This is because the amount of gas discharge can be small and a part for sealing can be small. However, in this case, there is a problem in that it is difficult to seal the ink filling opening part easily and securely.